Small square timber hewing machines are known in themselves in prior art. Such a small square timber hewing machine in its overall operation is disclosed in the Finnish. Pat. No. 37,065, published July 31, 1968, said patent is incorporated in the present application by specific reference thereto. The blades performing the hewing operation according to this Finnish Patent have the shape of a right angle with the apex of this angle pointing towards the cutter shaft, and wherein the blades have been arranged to rotate synchronously so that they intermesh adjacent to the square timber. Blades of this kind have the drawback that the blades perform the hewing motion in alternation and the square timber is set into vibration as the result of the hewing motion, and the cut is therefore unsatisfactory. Another drawback has been the lack of sharpness and the broken shape of the corner cut by the blade. Since the blade has the shape of a right angle, it follows that during the hewing motion at the apex of the angle the blade does not cut the square timber; instead, it tears off chips since chips that have already been detached remain in the corner, and as a consequence the result is not tidy.